My grandfather, Victor Hugo Benioff (1899-1968), was the only son of Simon Benioff, a Jewish immigrant from the Ukraine and a ladies tailor, and Aufrida Georgina (Hamilton) Widerquist (1861–1939), a Swedish immigrant and seamstress. He grew up in Los Angeles and went on to become a prominent seismologist and inventor of electric musical instruments. He was married twice, first to my grandmother Alice Pauline Silverman (1897-1988) and second to Mildred Ruth Lent (1920-2013). Later in life he lived in Mendicino with Mildred and their daughter. He died suddenly of heart disease on February 20, 1968.
“The Benioff vertical component seismometer works on the same principle as the telephone transmitter. Pendulum movement is converted into electric current by means of a variable reluctance transducer. A galvanometer, activated by this current, records the up-and-down component of ground motion. The instrument can monitor a broad range of seismic frequencies, depending on teh choice of galvanometer constants. From Benioff, “A New vertical seismograph,” BSSA, 22 (1932), Plate 13.”
Above from “Waves in the Earth: Seismology Comes to Southern California, by Judith R. Goodstein; Historical Studies in the Physical Sciences, Vol. 14, No. 2 (1984), pp.201-230, in the chapter entitled “Seismology At Caltech” p 210.
“During World War I Wood worked in the Army Corps of Engineers in Washington, D.C. on the problem of locating large guns using the sound waves from their detonation. While in Washington he convinced Arthur L. Day of the Carnegie Institution of the importance of studying southern California earthquakes. A Carnegie Committee on Seismology was appointed in 1921, and it recommended that Carnegie establish a network of seismograph stations in southern California. Wood was put in charge of this project (Wood, 1947), and he hired Hugo Benioff and Charles Richter to participate in this work. Benioff and J.A. Anderson of Carnegie’s Mount Wilson Astronomical Observatory were given the task of designing improved seismographs (Anderson and Wood, 1925; Benioff, 1932, 1935), and Richter began his life’s work of studying the earthquakes of southern California. Anderson’s short-period horizontal seismographs recorded local earthquakes (and teleseisms*) better than the long-period instruments then in use. These instruments were first used at the Mount Wilson Observatory office in Pasadena in 1922. A pair was also installed on the campus of the California Institute of Technology shortly thereafter (Goodstein, 1991). Benioff soon thereafter designed a companion vertical-component seismometer (as well as other instruments). “
From “History of the Seismological Society of America” by B.F. Howell, Jr., The Pennsylvania State University, Seismological Research Letters (Vol 73, No. 1, January/February 2002)”
* a teleseism is a tremor caused by an earthquake that is very far away